Method of making slide fasteners



P 11, 1951 e. WINTRISS 2,567,914

METHOD OF MAKING suns FASTENERS F1186. NOV. 15, 1947 FIG. I.

IN V EN TOR. 43 W M ATTORNEYS Patented Sept. 11, 1951 UNITED STATES :--PATENT OFFICE METHOD or MAKING sums FASTENERS Georg e Wintriss, Summit, N. J.

Application November 15, 1947, Serial No. 786,241

3 Claims. 29-148) This invention relates to the manufacture of slide fasteners and more especially to a method in which a part of the forming of each fastener element is done at the same station where the to the beaded edge of the tape is assured; and the apparatus for making the slide fasteners is simplified.

Another object of the invention is to provide a method of making slide fasteners in which the bead of the stringer tape is bent around a sharp curve just beyond the element-attaching station so as to shift the last-attached element into an angular position and move it back to a position that leaves the head of the next element unobstructed from above. This feature makes it possible to hold the next element in position by clamping force applied against the top and bottom surfaces of the head while the jaws of the element are being closed on the bead of the tape. In the preferred method of this invention the clamping of the element is done by the punch and die that coin the recess and projection in the head of the element. Without some provision for moving the last attached element out of the way it would not be possible to bring a punch into contact with the next element at the attaching station.

Space can be conserved, making possible the use of a larger coining punch, and more advantageous flow of the metal can be obtained, by having the punch move along a path at a slight angle to the direction of the tape bead at the attaching station. In conjunction with this slopisfactory methods is by ing path of the punch, the invention includes the I additional feature of an abutment with which the ends of the element jaws come in contact to po sition the element accurately at the attaching station and to prevent displacement of the element by the punch. This abutment feature is not limited to combinations in which a punch is brought against the elements at the attaching station.

Although various methods have been devised for making individual slide fastener elements from lengths of rod or strip, one of the most satcutting off slices of a rod that has been rolled to substantially a Y cross section. The outstanding advantage is that the cross section of the rod can be made to conform with the most advantageous outline for the-element that is to be sliced from the rod, and no concessions or compromises in the shapes of the spread jaws, head, or general outline of the element need be made to eliminate waste of material as is the case with many of the methods that make elements from flat strips or rods. In practice, however, the making of elements by slicing them from a rod of generally Y cross section has not lent itself to use in any simple apparatus for making and attaching the elements in a single machine.

It is another object of this invention to provide a method in which slide fastener element blanks can be sliced from a rod of appropriate cross section, formed with recesses and projections, and attached to a stringer tape in a simple and continuous operation without ever having the element blank free from the slicing, forming and attaching devices of the apparatus.

Other objects, features, and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing forming a, part hereof, in which like reference characters indicate corresponding parts in all the views,

Fig. 1 is a diagrammatic perspective view i1- lustrating the method of making slide fastener stringers in accordance with this invention.

Fig. 2 is a top plan view of a portion of the apparatus shown in Fig. l, the view being taken at the level of the attaching station.

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is an end view of the guide structure shown in Fig. 1.

Fig. 5 is a vertical view showing the way in which the stringer moves around the bend immediately above the attaching station.

Fig. 6 is a top plan view illustrating a different method for making the fastener elements.

In Fig. 1 the fastener elements are made by cutting off slices of a rod l2 that has a cross section shaped to the desired outline of the fastener elements. This cross-section is substantially a Y, and the branches of the Y constitute the spread jaws of the element.

The rod [2 is fed vertically by rollers I4 along the rearward surface of a slicing die 16 which is shaped to fit the front face of the rod l2. The operation of the feed rollers I4 is intermittent,

the rod 12 being advanced for a distance equal to the desired thickness of a fastener element with each cycle of the operation of the machine. The portion of the rod [2 projecting above the top edge of the die 16 is sliced off by a shear blade H as this blade moves forward.

A recess 18 in the shear blade 11 is shaped to fit the back and side faces of the rod I2 so that a fastener element 20 sliced from the end of the rod I2 is held by the recess I8 against transverse displacement while the blade l1 pushes the fastener element forward to an attaching station.

Although the element 20, as it is sliced from the rod I2, does not have slopin slide walls around the head, or a recess and projection for interlocking it with other fastener elements, and is to that extent unfinished, it will be referred to herein as a fastener element, no distinction in terminology being made between partially and fully finished elements.

At the attaching station the ends of the spread jaws contact with a front wall 22 of a guide structure 23. The abutment provided by this front wall serves as a limit stop for positioning the element 2!] at the attaching station. A stringer tape 25 extends through a slot 26 in the guide structure 23 and the head 21 of the tape is positioned in front of the guide structure so that the spread jaws of the element 29 are astride the bead of the tape when the element is located at the attaching station with the ends of the spread jaws in contact with the wall 22 of the guide structure.

In order to position the bead 21 out in front of the wall or limit stop 22 so that the jaws of the element 20 will extend around behind the bead when closed, the guide structure 23 below the attaching station projects further forward and into contact with the back of the bead along the region indicated in Fig. by the reference character 29. Above the attaching station, the guide structure 23 curves sharply in a direction away from the fastener element 20. The purpose of this curved guide structure will be explained in connection with the final forming of the elements.

Referring to Figs. 1 and 3, the fastener element 20, when at the attaching station, has its head portion located above a coining die 30. The jaws of the fastener element project beyond the end of this die 30. A coining punch 32 is brought down against the top surface of the fastener element and clamps the element against the die 30. Continued movement ofthe punch 32 forces the punch into the fastener element and causes a flow of metal downward into the die 30. This coining or drawing operation produces a recess in the surface of the upper face, a corresponding projection on the lower face, and sloping edges around the head portion of the element for most of the height of the element.

In describing this forming of the element head as a coining operation, the term coining is used in a broad sense to designate a drawing operation with at least partial confinement of the element on the sides. This method of shaping the beads gives the heads the most advantageous shape and is superior to those methods in which the fastener elements are served from continuous strips and have substantially straight side walls corresponding to the sides of the strip, and have side walls for the jaws that are the same as the side walls of the head.

The blade i1 is withdrawn after the element 20 is firmly clamped in position by the punch 32 and die 30. The path of movement of the punch 32 is preferably at a slight angle to the direction in which the tape extends through the fastener element; that is, instead of moving in a direction normal to the top surface of the fastener element, the punch 32 moves along a path that slopes downward toward the guide surface 22. This sloping path of movement of the punch is not an essential feature of the invention, but it has two advantages. One is space conservation resulting from the fact that the punch slopes away from the fastener elements that are already attached to the tape; the other is a smoother flow of the metal caused by more symmetrical distribution of the die space around the path followed by the punch through the metal. The abutment surface or limit stop 22 prevents any endwise displacement of the fastener element such as might result from the sloping path of the punch 32 if the ends of the jaws were not in contact with a limit stop.

While the fastener element 20 is firmly held at the attaching station by the punch 32 and die 30, the jaws of the fastener element are closed to grip the bead of the tape. This operation bends the jaws from the dotted line positions shown in Fig. 2 to the full line positions in which the element is firmly secured to the stringer tape. The jaws are closed by hammers operated by wins in a manner well understood in the art.

As soon as the element 20 is secured on the tape, the punch 32 withdraws and the tape advances for a distance equal to the desired spacing of the elements on the tape, thus bringing a new region of the tape to the attaching station and into position for receiving the next fastener element. The tape 25 is moved by feed rolls 34 which grip the portion of the tape back of the bead 21. In some machines the tape feed rolls have recesses in their faces for receiving the bead also.

Above the attaching station, the tape 25 passes around a sharp curve of the guide structure 23. This sharp bend of the tape moves the fastener elements forward away from the path of the punch 32 and tilts the last-attached fastener element upward into an angular position in which it does not obstruct access from above to the head portion of the next fastener element at the attaching station. The fastener element 36 (Fig. 1) is in the moved-back, tilted position caused by the initial curve of the guide structure 23 and the resulting bend in the tape. Above the fastener element 36 there are other attached elements 31 advancing with the tape around the continuing curve of the guide structure. Walls 38 on both sides of the guide surface 22 hold the fastener elements 31 against transverse displacement. These guide walls 31 begin a short distance above the attaching station. The hammers that close the jaws of the fastener elements prevent transverse displacement of the element at the attaching station.

The radius of curvature of the wall 22 around which the bead 21 bends immediately above the attaching station must be short enough to move the fastener element 36 far enough back and into a sufficiently tilted position to provide clearance for the punch 32. It will be evident that if this first fastener element 35 is clear of the path of the punch 32, all of the higher elements 31 will also be out of the way of the punch. The actual radius used depends upon the spacing of the elements from one another on the tape and upon the length of the head portions of the elements,

' that is the distance that they extend from the bead of the tape.

The inner ends of the closed jaws of the fastener elements 36 and 31 slide along the curved portion of the wall 22 and hold the bead 21 of the tape spaced 9. small distance from the wall 22. Since the fastener elements 36 and 31 are guided by the walls 38, and the tape 25 is gripped firmly by these fastener elements, the walls 38 serve to guidethe tape indirectly.

Further guiding of the tape 25 is provided by the slot 26 but it is a feature of the invention that the walls of the slot 26 diverge from one another away from the bead 21, at least at the curved portion of the guide structure 23 so as to permit the tape 25 to buckle at the curve. Even at its minimum width, the slot 28 is wide enough to permit a slight buckling of the tape, but the amount of buckle that must be provided for increases progressively toward the center of curvature.

Although the slicing of fastener elements from a bar of substantially Y cross section is used in the preferred method of this invention, some features of the invention can be emp oyed with fastener elements made from fiat strips.

Fig. 6 shows a strip 40 that is first out along the edges by dies which cut out triangu ar notches 42. An element 43 is then severed from the strip 40 along a curved line 44 that outlines the head portion of the element 43 and the space between the spread jaws of the next element that will be severed from the strip. With this method of making the fastener elements. the head of one element is nested between the spread jaws of the next element and the strip 40 is advanced until the ends of the spread jaws of the endmost element come into contact with the same limit stop as in Figs. 1 and 3. The head portionof the element 43 (Fig. 6) is located over the die 33 (Fig. 3) and the punch 32 is brought down, as previously explained, to form a depression in the top surface, a projection on the bottom surface, and to give the sides of the head portion a slope.

Fig. 6 shows an endmost element 46 with its head portion nested within the spread jaws of the element 43. The coining of the head portion of the element by the punch pushes the element down into the die and thus lowers the level of the endmost element, but with elements of moderate height this lowering of the level is not sufficient to move the entire element below the original plane of the bottom surface. This is illustrated in Fig. 3 where the element 29 is moved from the dotted line position to the full line position by the operation of the punch 32 in pushing the head portion of the element 20 down into the die 30. With the nested elements 43 and 46, therefore, the depression of the endmost element 46 by the coining punch will not move the head of that element out of the space in which it is nested between the spread jaws of the next element 43. Even if the endmost element 46 were depressed below the level of the spread jaws of the next element 43 by which it is held in line as it is fed forward to the attaching station, no harm would be done because the coining punch and die hold the endmost element against lateral displacement after the element is confined between them.

The jaws of the element are closed. on the tape while the element is held down in its depressed position in the coining die. The subsequent movement of the tape carries the attached element above its original level and the upward tilting of the element by the curve around which and the feature of bending the bead with the attached elements around a sharp curve just above the attaching station can be combined with clamping means for gripping the fastener ele ment, by means that contact with the top face of the element, whether or not such gripping means also serve as forming apparatus for shaping the fastener element. Other modifications can be made and some features of the invention can be used alone or in different combinations. Terms of orientation in the description and claims are of course, relative.

What is claimed is:

1. In the manufacture of slide fastener stringers having spaced fastener elements clamped to a bead along one edge of a tape, the method that comprises advancing the bead and the last-attached fastener element longitudinally for a predetermined distance after each fastener element is attached to the 'bead, and during such advance bending the bead out of line with its direction of extent at the station where the fastener element was attached to the bead, the bend being sufliciently sharp to clear a space of substantial extent above the attaching station that would be obstructed by the last-attached fastener element were it not for said bending of the bead, advancing an embryo fastener element transversely of the bead and into a position at the at aching station with jaws of said fastener element straddling the bead of the tape, and while the fastener element is in this position with its jaws straddling the tape forming a recess in one face of the element and a corresponding projection in the opposite face by bringing a tool down into said space above the attaching station and into contact with the embryo fastener element to complete the forming of the fastener element. closing the aws of the element on the bead of the tape while the element remains in the position at which the recess and projection were formed, and again advancing the bead and the last-attached fastener element longitudinally and during such advance bending the bead to again provide said space above the attaching station.

2. In the manufacture of slide fastener stringers having spaced fasten r elements clamped to a bead along one edge of a tape, the method that comprises severing successive embryo fastener elements from a bar at a region adjacent to an attaching station and as a continuous operation with the severing of each successive embryo element, positioning said embryo element astride the bead at the attaching station. and while the fastener element is in this position astride the tape, forming a recess in one face of the element and a corresponding projection in the opposite face by bringing a tool down into the space above the attaching station and into contact with the embryo fastener element at said station to complete the forming of the fastener element, closing the fastener element on the bead of the tape while the element remains in the position at which the recess and projection were formed, advancing the bead and the attached fastener element longitudinally for a predetermined distance after the fastener element is attached to the bead, and during such advance bending the bead out of line with its direction of extent at the station where the fastener element was attached to the bead, the bend being sufficiently sharp to clear a space, of substantial extent above the attaching station, that would be obstructed by the last-attached fastener element were it not for said bending of the bead, severing another embryo fastener element from the bar and repeating the cycle with this and the successive embryo fastener elements to complete a stringer having uniformly spaced fastener elements clamped to the bead along its length.

3. In the manufacture of slide fastener stringers having spaced fastener elements clamped to a bead along one edge of a tape, the method that comprises advancing the bead and the lastattached fastener element longitudinally for a predetermined distance after each fastener ele ment is attached to the bead, and during such advance bending the bead out of line with its direction of extent at the station where the fastener element was attached to the head, the bend being sufficiently sharp to clear a space of substantial extent above the attaching station that would be obstructed by the last-attached fastener element were it not for said bending of the bead, shearing an embryo element' from a bar that has a transverse cross section with the desired shape of a fastener element having spread jaws for straddling the bead of the tape, positioning the bar so that each embryo fastener element sheared from the top of the bar is moved by the shearing operation into position at the attaching station with the spaced jaws of the embryo fastener element straddling the bead of the tape, and while the fastener element is in this position with its jaws straddling the tape forming a recess in one face of the element and a corresponding projection in-the opposite face by bringing a tool down into said space above the attaching station and into contact with the embryo fastener element to complete the forming of the fastener element, closing the jaws of the element on the bead of the tape while the element remains in the position at which the recess and projection were formed, and again advancing the bead and the last-attached fastener element longitudinally and during such advance bending the head to again provide said space above the attaching station.

GEORGE WIN'I'RISS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,467,015 Sundback Sept. 4, 1923 1,966,256 Marinsky July 10, 1934 2,078,017 Poux Apr. 20, 1937 2,106,129 Sundback Jan. 18, 1938 2,141,200 Sundback Dec. 27, 1938 2,221,740 Ulrich Nov. 12, 1940 2,299,606 Wintritz Oct. 20, 1942 2,335,034 Winterhalter Nov. 23, 1943 

